<?php
$conn1=new MySQLi("localhost","User","Passwort","Datenbank");
if($conn1->connect_errno){
    echo mysqli_connect_error();
    exit;
}
$res=$conn1->query("show tables") or die($conn1->error); while($tables=$res->fetch_array()){
    $conn1->query("ALTER TABLE $tables[0] CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci") or die($conn1->error); } echo "The collation of your database has been successfully changed!";
 
$res->free();
$conn1->close();
 
?>